Semiconductor package having an EMI shielding layer

ABSTRACT

Semiconductor packages and methods of forming semiconductor packages are described. In an example, a semiconductor package includes a shielding layer containing metal particles, e.g., conductive particles or magnetic particles, in a resin matrix to attenuate electromagnetic interference. In an example, the shielding layer is transferred from a molding chase to the semiconductor package during a polymer molding operation.

PRIORITY

The present patent application is a continuation of and claims thebenefit of U.S. patent application Ser. No. 15/089,328, titled“Semiconductor Package Having An EMI Shielding Layer,” filed Apr. 1,2016, which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

Embodiments of the invention are in the field of semiconductor packagesand, in particular, semiconductor packages having electromagneticinterference shielding and methods of forming such semiconductorpackages.

BACKGROUND

Semiconductor packages incorporating integrated circuits are subject todisturbances by electromagnetic interference. Accordingly, to shieldsemiconductor packages from electromagnetic interference, a moldedsurface of the semiconductor package may be coated with a conductivematerial. For example, the conductive material may be sputtered on themolded surface using a physical vapor deposition (PVD) process. Thecoating process may also include spraying or painting the conductivematerial on the molding the molded surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a sectional view of a semiconductor package assembly,in accordance with an embodiment.

FIG. 2 illustrates a sectional view, taken about line A-A of FIG. 1, ofa semiconductor package having a shielding layer, in accordance with anembodiment.

FIG. 3 illustrates a sectional view, taken about line A-A of FIG. 1, ofa semiconductor package having a shielding layer electrically connectedto a package substrate, in accordance with an embodiment.

FIG. 4 illustrates a semiconductor package assembly having a shieldinglayer electrically connected to a circuit board, in accordance with anembodiment.

FIG. 5 illustrates a method of fabricating a semiconductor packagehaving a shielding layer, in accordance with an embodiment.

FIG. 6 illustrates an operation in a method of fabricating asemiconductor package having a shielding layer, in accordance with anembodiment.

FIG. 7 illustrates a sectional view, taken about line B-B of FIG. 6, ofa mold release film used in a method of fabricating a semiconductorpackage having a shielding layer, in accordance with an embodiment.

FIG. 8 illustrates a perspective view of a die strip used in a method offabricating a semiconductor package having a shielding layer, inaccordance with an embodiment.

FIG. 9 illustrates a sectional view, taken about line C-C of FIG. 8, ofa die strip having a shielding layer, in accordance with an embodiment.

FIG. 10 illustrates a sectional view, taken about line C-C of FIG. 8, ofa die strip having a shielding layer electrically connected to a packagesubstrate, in accordance with an embodiment.

FIG. 11 is a schematic of a computer system, in accordance with anembodiment.

DESCRIPTION OF EMBODIMENTS

Semiconductor packages having shielding layers to attenuateelectromagnetic interference (EMI) are described. In the followingdescription, numerous specific details are set forth, such as packagingand interconnect architectures, in order to provide a thoroughunderstanding of embodiments of the present invention. It will beapparent to one skilled in the art that embodiments of the presentinvention may be practiced without these specific details. In otherinstances, well-known features, such as specific semiconductorfabrication processes, are not described in detail in order to notunnecessarily obscure embodiments of the present invention. Furthermore,it is to be understood that the various embodiments shown in the Figuresare illustrative representations and are not necessarily drawn to scale.

Existing EMI shields for semiconductor packages, and methods used tofabricate such shields, have several shortfalls. For example, thetooling used to apply a conductive material using vacuum deposition canbe costly. Furthermore, in the case of spray or paint-based EMIshielding, a high presence of volatile organic compound raisesenvironmental concerns. Existing EMI shielding methods can also becostly or difficult to control. For example, extended throughput time isrequired to increase conductive material thickness, adding to per unitcosts. Furthermore, a uniform material coverage on package sidewalls canbe difficult to achieve. Also, the processes may be form factor limited,meaning that the conductive material may not be able to reach or obtaina desired thickness within deeper regions of the package. Compoundingthese shortfalls, an EMI shield fabricated by existing methods may onlyattenuate EMI having a narrow frequency band, and thus, may not befunctionally optimal.

In an aspect, a semiconductor package includes a shielding layer toattenuate EMI. The shielding layer may include metal particles in aresin matrix. More particularly, the shielding layer may be a portion ofa mold release film that is transferred from a molding chase to asemiconductor package during a molding process. Accordingly, theshielding layer may be applied to the semiconductor package in alow-cost and efficient process having low levels of volatile organiccompounds. The mold release film, and thus the shielding layer, may beuniform and include a predetermined thickness in the nm, micron, or milrange. Furthermore, the metal particles may include conductive particlesor magnetic particles having various materials or material properties,and thus, the metal particles may endow the shielding layer with anability to attenuate EMI having a broad band of both low and highfrequencies.

Referring to FIG. 1, a sectional view of a semiconductor packageassembly is shown in accordance with an embodiment. Semiconductorpackage assembly 100 may include a semiconductor package 102 mounted ona circuit board 104, e.g., a motherboard or another printed circuitboard of a computer. Semiconductor package 102 may be one of any of thevarious types of known semiconductor packages 102. For example,semiconductor package 102 may have a system in package (SiP) designhaving one or more integrated circuits enclosed in a single module.Semiconductor package 102 may include solder balls attached tocorresponding contacts on circuit board 104. Solder balls may functionas power/ground pins or as signal pins for I/O of semiconductor package102.

In an embodiment, semiconductor package 102 includes a top packageportion 106, e.g., a heat spreader, which forms a shell above a packagesubstrate 108. More particularly, top package portion 106 may beovermolded on package substrate 108 to enclose a semiconductor die 110,e.g., a silicon-based integrated circuit, of semiconductor package 102.Semiconductor die 110 may be mounted on package substrate 108.Accordingly, package substrate 108 may act as an intermediate structureto mount semiconductor die 110 on circuit board 104 and to carryelectrical signals between semiconductor die 110 and circuit board 104.

Referring to FIG. 2, a sectional view, taken about line A-A of FIG. 1,of a semiconductor package having a shielding layer is shown inaccordance with an embodiment. Semiconductor package 102 may include apolymer layer 202 over semiconductor die 110. For example, polymer layer202 may include a cured, injectable liquid polymer covering severalsides of semiconductor die 110. More particularly, polymer layer 202 mayencapsulate semiconductor die 110 over package substrate 108. Forexample, a bottom surface of semiconductor die 110 may be mounted onpackage substrate 108, and polymer layer 202 may cover and contact a topand peripheral sides of semiconductor die 110 above package substrate108.

In an embodiment, semiconductor package 102 includes a shielding layer204 over polymer layer 202. More particularly, shielding layer 204 mayinclude a resin matrix 206 covering a top surface of polymer layer 202above semiconductor die 110. Resin matrix 206 may be loaded with metalparticles 208. That is, several metal particles 208 may be embedded inresin matrix 206. Resin matrix 206 may be formed from any of varioustypes of resin materials. For example, resin matrix 206 may include anepoxy, acrylic, epoxy-acrylic, urethane blend, urethane, siliconeneoprene, or other types of epoxies, hybrid materials, elastomers, etc.

Metal particles 208 in resin matrix 206 may attenuate EMI, and moreparticularly, a type of metal particle 208 may be selected to attenuateEMI having a predetermined frequency or range of frequencies. In anembodiment, metal particles 208 include magnetic particles 210. Magneticparticles 210 may provide EMI shielding based on absorption ofelectromagnetic energy. For example, magnetic particles 210 may absorbmicrowave or other radio frequency interference signals that pose apotential disturbance to the efficacy of semiconductor package 102.Since EMI shielding provided by magnetic particles 210 is based onabsorption of energy, shielding layer 204 may not require electricalgrounding.

Magnetic particles 210 may include various shapes and materials. Forexample, magnetic particles 210 may be spherical particles, or may havean irregular shape, e.g., flakes, fibers, filings, etc. Magneticparticles 210 may incorporate a magnetic material such as ferrites,nickel-zinc, or iron. By way of example, magnetic particles 210 mayinclude powdered iron fillers that are mixed into resin matrix 206 andtransferred onto polymer layer 202 as described below.

The material used to form metal particles 208 may control an attenuationrange of shielding layer 204. For example, in the case of magneticparticles 210 described above, magnetic particles 210 may attenuate EMIhaving a frequency in a range of 500 MHz to 18 GHz. Accordingly,shielding layer 204 may include one or more different types of magneticparticles 210 to attenuate a predetermined frequency band of EMI. Thatis, a first type of magnetic particle 210 having a first magneticmaterial may be loaded in resin matrix 206 to attenuate a firstfrequency range of EMI, and a second type of magnetic particle 210having a second magnetic material may be loaded in resin matrix 206 toattenuate a second frequency range of EMI. Accordingly, an ability ofshielding layer 204 to attenuate EMI may be tuned as needed.

Referring to FIG. 3, a sectional view, taken about line A-A of FIG. 1,of a semiconductor package having a shielding layer electricallyconnected to a package substrate is shown in accordance with anembodiment. Metal particles 208 may include conductive particles 302.Conductive particles 302 in resin matrix 206 may attenuate EMI, and moreparticularly, conductive particles 302 may shield EMI based onconduction. Accordingly, conductive particles 302 may be electricallyconnected to each other in resin matrix 206.

Electrical conductivity of conductive particles 302 in resin matrix 206may be provided by loading conductive particles 302 into resin matrix206 with a sufficient density to ensure that conductive particles 302touch to create a conductive path across a lateral plane of shieldinglayer 204. For example, an epoxy resin matrix 206 may contain 70-80% byvolume conductive particles 302, such that, on average, conductiveparticles 302 are closely packed and in contact with adjacent conductiveparticles 302.

Conductive particles 302 may include various shapes. For example,conductive particles 302 may be spherical particles, or may have anirregular shape, e.g., a flake, fiber, strand, filing, etc., which maybe on a nm or micron scale. In an embodiment, irregularly shapedconductive particles 302 may allow for more particles to be packed intoresin matrix 206 per unit volume. Accordingly, irregularly shapedconductive particles 302 may increase a conductivity of shielding layer204.

Conductive particles 302 may include various materials. For example,conductive particles 302 may include nickel or silver-plated copper orstainless steel, silver-plated aluminum, silver-plated glass,silver-nickel, sintered metal pastes, or other alloys or silver-basedconductive particles 302.

As described above, the material used to form metal particles 208 maycontrol an attenuation range of metal particles 208. For example, in thecase of conductive particles 302 described above, conductive particles302 may attenuate EMI having a frequency in a range greater than 1 GHz.By way of example, conductive particles 302 formed from nickel andsilver-plated copper particle resin blends may provide an EMIattenuation in a range greater than 65 dB. Also by way of example,conductive particles 302 formed from silver may provide an EMIattenuation in a range of 80-90 dB, e.g., 85 dB. Accordingly, shieldinglayer 204 may include one or more different types of conductiveparticles 302 to attenuate a predetermined frequency band of EMI.

Shielding layer 204 may be electrically grounded. More particularly,conductive particles 302 in resin matrix 206 may be electricallyconnected to package substrate 108 of semiconductor package 102. In anembodiment, shielding layer 204 is electrically connected to a groundingpad 304 on package substrate 108. Grounding pad 304 may be a conductivecontact, e.g., a deposited copper pad, on an upper surface of packagesubstrate 108. Thus, grounding pad 304 may be laterally besidesemiconductor die 110 and may also be encapsulated by polymer layer 202.

In an embodiment, shielding layer 204 is electrically connected togrounding pad 304 by a via 306. Via 306 may extend through shieldinglayer 204 and/or polymer layer 202 to grounding pad 304. Moreparticularly, via 306 may include a conductive material, e.g., copper,filling a via hole laser drilled through conductive particles 302, resinmatrix 206, and polymer layer 202. Thus, via 306 may be electricallyconnected to conductive particles 302 and grounding pad 304 toelectrically ground shielding layer 204 to package substrate 108.

Semiconductor package 102 may include a shielding layer 204 having bothmagnetic particles 210 and conductive particles 302. For example,shielding layer 204 may include a first layer 308 and a second layer 310containing respective types of metal particles 208. In an embodiment,first layer 308 includes conductive particles 302 electrically connectedto each other in resin matrix 206, as described above. Second layer 310,by contrast, may include magnetic particles 210 in resin matrix 206, asdescribed above with respect to FIG. 2. Thus, shielding layer 204 mayprovide hybrid functionality by attenuating EMI based on both conductionand absorption. That is, shielding layer 204 may shield a broad band ofEMI frequencies according to the types of conductive particles 302 andmagnetic particles 210 included in resin matrix 206 of shielding layer204.

In an embodiment, shielding layer 204 includes a mixture of conductiveparticles 302 and magnetic particles 210 within a same lateral plane(not shown). For example, first layer 308 having conductive particles302 and second layer 310 having magnetic particles 210 may be a samelayer. Accordingly, magnetic particles 210 may be interspersed betweenconductive particles 302 of shielding layer 204. When conductiveparticles 302 are loaded in resin matrix 206 at a sufficient density,e.g., greater than 50% by volume, conductivity of shielding layer 204may be maintained even though some conductive particles 302 may beseparated from other conductive particles 302 by one or more magneticparticles 210. Thus, the hybrid functionality of shielding layer 204having both conductive particles 302 and magnetic particles 210 may bemaintained.

Referring to FIG. 4, a semiconductor package assembly having a shieldinglayer electrically connected to a circuit board is shown in accordancewith an embodiment. Semiconductor package assembly 100 may includesemiconductor packages 102, as described above, mounted on circuit board104. More particularly, circuit board 104 may be electrically connectedto semiconductor package 102 having shielding layer 204 loaded withmetal particles 208. In a case of shielding layer 204 having conductiveparticles 302 electrically connected to each other in resin matrix 206,shielding layer 204 may be electrically connected to grounding pad 304on circuit board 104. That is, grounding pad 304 may be formed oncircuit board 104 rather than package substrate 108, and thus, shieldinglayer 204 may be electrically grounded to circuit board 104 at the boardlevel rather than package substrate 108 at the package level.

In an embodiment, a grounding structure 402 extends from shielding layer204 to grounding pad 304 on circuit board 104. For example, groundingstructure 402 may include a metallized can or metallized cloth attachedto shielding layer 204 at a first contact point and to grounding pad 304at a second contact point. Alternatively, grounding structure 402 mayinclude an electrical lead, e.g., a conductive wire, attached toshielding layer 204 at the first contact point and to grounding pad 304at the second contact point. Grounding structure 402 may include asputtered film as well. For example, a sputtering process may be appliedto semiconductor package 102 attached to circuit board 104 such that asputtered film is grown across a portion of shielding layer 204 andalong a peripheral side of semiconductor package 102 to extend to andoverlap grounding pad 304 on circuit board 104. Accordingly, shieldinglayer 204 may be grounded to package substrate 108 or to circuit board104 in numerous manners.

Semiconductor package 102 having shielding layer 204 to attenuate EMImay be formed in a method that includes transferring shielding layer 204to polymer layer 202 as part of a polymer molding operation. Referringto FIG. 5, a method of fabricating a semiconductor package having ashielding layer is shown in accordance with an embodiment. The methodcorresponds to depictions represented in FIGS. 6-8, and thus, shall bedescribed below with alternating reference to each of those figures.

Referring to FIG. 6, an operation in a method of fabricating asemiconductor package having a shielding layer is shown in accordancewith an embodiment. At operation 502, a mold release film 606 may beapplied to or onto a recessed surface 602 of a molding chase, e.g., atop molding chase 604. For example, mold release film 606 may beprovided in a roll format. The roll of film may be fed into the moldingtool by transmission mechanisms such as roller systems of existingmolding equipment. Accordingly, after feeding mold release film 606 intothe tool, a vacuum may be applied to suction mold release film 606against relief features of top molding chase 604. More particularly,mold release film 606 may be held against recessed surface 602 by thevacuum suction. Alternatively, mold release film 606 may be applied onrecessed surface 602 using other techniques, e.g., by coating recessedsurface 602 with mold release film 606. Mold release film 606 mayinclude one or more layers, and at least one of the layers may beshielding layer 204. Thus, mold release film 606 may contain metalparticles 208, e.g., conductive particles 302, in resin matrix 206.

Recessed surface 602 may include a portion of a surface of a top moldingchase 604 facing a lower molding chase 608. In an embodiment, recessedsurface 602 is lowered into place over semiconductor die 110 and packagesubstrate 108. More particularly, at operation 504, upper molding chase604 may be placed over package substrate 108 and/or lower molding chase608 to create a compartment 612 between recessed surface 602 and packagesubstrate 108. For example, package substrate 108 may be moved intocompartment 612 of the molding tool by handling systems. Compartment 612may be between shielding layer 204 of mold release film 606 and an uppersurface of package substrate 108. Upper molding chase 604 may be moveddown to clamp over package substrate 108. That is, upper molding chase604 may clamp down on a surface of lower molding chase 608 to enclosepackage substrate 108 in compartment 612. Accordingly, semiconductor die110 may be mounted on package substrate 108 within compartment 612 whenupper molding chase 604 is set against lower molding chase 608.

At operation 506, a polymer 610 may be transferred into compartment 612.More particularly, the transferred polymer 610 may form polymer layer202 over semiconductor die 110 by filling compartment 612 betweenshielding layer 204 of mold release film 606 and package substrate 108.Accordingly, the transferred polymer 610 may form polymer layer 202 oversemiconductor die 110.

Transferring polymer 610 may occur in a molding process of any kind. Forexample, polymer 610 may be injected, i.e., transferred in an injectionmolding process. Furthermore, polymer 610 may be transferred, i.e.,transferred in a transfer molding process. Accordingly, this descriptionapplies to all types of molding processes. That is, compartment 612 maybe filled by polymer 610 in any type of molding process. After fillingcompartment 612 with polymer 610, at least a portion of polymer layer202 may be in contact with shielding layer 204. Thus, shielding layer204 and polymer layer 202 may appose each other in preparation forreleasing shielding layer 204 onto polymer layer 202.

Referring to FIG. 7, a sectional view, taken about line B-B of FIG. 6,of a mold release film used in a method of fabricating a semiconductorpackage having a shielding layer is shown in accordance with anembodiment. Mold release film 606 on upper molding chase 604 may includeseveral separate layers. For example, in addition to shielding layer 204containing metal particles 208, mold release film 606 may include a basefilm 702. Base film 702 may be applied to upper molding chase 604between recessed surface 602 and shielding layer 204 as described above.Thus, base film 702 may provide an intermediate film layer betweenshielding layer 204 and upper molding chase 604.

In an embodiment, base film 702 is a film or foil having a low glasstransition temperature. For example, the glass transition temperature ofbase film 702 may be in a range of 80-125° C. For example, base film 702may include polyethylene terephthalate (PET), ethylenetetrafluoroethylene (ETFE), or polystyrene-based films. ETFE typicallyincludes a glass transition temperature ranging from 80-90° C., andpolystyrene and PET-based films typically include a glass transitiontemperature ranging from 100-115° C. in an embodiment, base film 702 hasa laminated structure, e.g., a bilayer structure, incorporating layershaving different glass transition temperatures, and thus, base film 702may be tuned to provide the mechanical properties necessary to releaseshielding layer 204 onto polymer layer 202, as described below.

At operation 508, shielding layer 204 may be transferred from recessedsurface 602 to polymer layer 202. That is, the metallized shieldinglayer 204 may be designed to be released and transferred to polymer 610during the molding process. For example, the transfer of shielding layer204 may occur when the transferred polymer 610 is being cured withincompartment 612. Since the lamination of shielding layer 204 on polymerlayer 202 is integral to the curing process, additional tooling orequipment may not be required for EMI shielding.

Polymer 610 may be cured during the molding process through theapplication of elevated temperatures. For example, the molding chase maybe subjected to molding conditions, i.e., high temperatures, provided byan oven. In an embodiment, as a temperature of base film 702 having alow glass transition temperature and resin matrix 206 of shielding layer204 increases, base film 702 and shielding layer 204 may separate andthe conductive matrix may adhere to the cured polymer layer 202 to forman EMI shield over polymer layer 202, semiconductor die 110, and packagesubstrate 108. Curing of polymer 610 may occur in an oven at atemperature higher than 100° C., e.g., 175° C. for more than 1 hour,e.g., 4-5 hours. Thus, as polymer 610 cures and a temperature of moldrelease film 606 increases, shielding layer 204 may slowly release frombase film 702 to attach to polymer layer 202.

Referring to FIG. 8, a perspective view of a die strip used in a methodof fabricating a semiconductor package having a shielding layer is shownin accordance with an embodiment. A die strip 802 may include a sheet ofpackage substrate 108 material having several semiconductor dies 110mounted on the sheet. For example, die strip 802 may contain tens tohundreds, e.g., 40-200, individual silicon-based semiconductor dies 110mounted in a matrix pattern on package substrate 108. Accordingly, diestrip 802 may be processed in a molding chase as described above. Moreparticularly, several semiconductor dies 110, e.g., every semiconductordie 110 of die strip 802, may be disposed within compartment 612 whenupper molding chase 604 is placed over package substrate 108 of diestrip 802. Accordingly, polymer layer 202 may be simultaneously formedover semiconductor dies 110 of die strip 802 during a single moldingprocess. Thus, shielding layer 204 may be simultaneously released ontoan entire upper surface of die strip 802 during the molding processusing standard film-assisted molding chase equipment.

Referring to FIG. 9, a sectional view, taken about line C-C of FIG. 8,of a die strip having a shielding layer is shown in accordance with anembodiment. After the molding process, the molding chases 604, 608 maybe separated and the resultant die strip 802 having shielding layer 204may be removed from the molding equipment. In an embodiment, theresultant die strip 802 includes several semiconductor dies 110 mountedon package substrate 108 and polymer layer 202 covered by shieldinglayer 204. Shielding layer 204 may include conductive particles 302and/or magnetic particles 210 in resin matrix 206. Thus, the resultantdie strip 802 may be singulated to produce several individualsemiconductor packages 102 or semiconductor package assemblies 100 asshown and described with respect to FIGS. 2 and 4.

Referring to FIG. 10, a sectional view, taken about line C-C of FIG. 8,of a die strip having a shielding layer electrically connected to apackage substrate is shown in accordance with an embodiment. Groundingpads 304 may be formed on die strip 802 prior to the molding process.Accordingly, forming polymer layer 202 over semiconductor dies 110 mayalso cover grounding pads 304. Thus, after removing the resultant diestrip 802 from the molding chase equipment, vias 306 may be opened,e.g., using a laser milling process, and a conductive epoxy may beinserted into the via holes to connect conductive particles 302 inshielding layer 204 to grounding pads 304. Thus, shielding layer 204 maybe electrically connected to grounding pads 304 on package substrate 108through polymer layer 202. The resultant die strip 802 having aconductive shielding layer 204 may be singulated to produce severalindividual semiconductor packages 102 or semiconductor packageassemblies 100 as shown and described with respect to FIG. 3.

Singulated semiconductor packages 102 may proceed with subsequentprocess operations for package level assembly and/or board levelassembly. For example, package level assembly may proceed, e.g., byattaching solder balls to package substrate 108 and/or mounting toppackage portion 106 over the singulated semiconductor package 102.Similarly, board level assembly may proceed, e.g., by attaching thesolder balls of semiconductor package 102 to circuit board 104 and/orattaching grounding structure 402 between shielding layer 204 and agrounding pad 304 on circuit board 104 to electrically connect shieldinglayer 204 to the grounding pad 304.

FIG. 11 is a schematic of a computer system, in accordance with anembodiment. The computer system 1100 (also referred to as the electronicsystem 1100) as depicted can embody a semiconductor package having ashielding layer containing metal particles, e.g., conductive particlesor magnetic particles, in a resin matrix to attenuate electromagneticinterference, according to any of the several disclosed embodiments andtheir equivalents as set forth in this disclosure. The computer system1100 may be a mobile device such as a netbook computer. The computersystem 1100 may be a mobile device such as a wireless smart phone. Thecomputer system 1100 may be a desktop computer. The computer system 1100may be a hand-held reader. The computer system 1100 may be a serversystem. The computer system 1100 may be a supercomputer orhigh-performance computing system.

In an embodiment, the electronic system 1100 is a computer system thatincludes a system bus 1120 to electrically couple the various componentsof the electronic system 1100. The system bus 1120 is a single bus orany combination of busses according to various embodiments. Theelectronic system 1100 includes a voltage source 1130 that providespower to the integrated circuit 1110. In some embodiments, the voltagesource 1130 supplies current to the integrated circuit 1110 through thesystem bus 1120.

The integrated circuit 1110 is electrically coupled to the system bus1120 and includes any circuit, or combination of circuits, according toan embodiment. In an embodiment, the integrated circuit 1110 includes aprocessor 1112 that can be of any type. As used herein, the processor1112 may mean any type of circuit such as, but not limited to, amicroprocessor, a microcontroller, a graphics processor, a digitalsignal processor, or another processor. In an embodiment, the processor1112 includes, or is coupled with, a semiconductor package having ashielding layer containing metal particles, e.g., conductive particlesor magnetic particles, in a resin matrix to attenuate electromagneticinterference, as disclosed herein. In an embodiment, SRAM embodimentsare found in memory caches of the processor. Other types of circuitsthat can be included in the integrated circuit 1110 are a custom circuitor an application-specific integrated circuit (ASIC), such as acommunications circuit 1114 for use in wireless devices such as cellulartelephones, smart phones, pagers, portable computers, two-way radios,and similar electronic systems, or a communications circuit for servers.In an embodiment, the integrated circuit 1110 includes on-die memory1116 such as static random-access memory (SRAM). In an embodiment, theintegrated circuit 1110 includes embedded on-die memory 1116 such asembedded dynamic random-access memory (eDRAM).

In an embodiment, the integrated circuit 1110 is complemented with asubsequent integrated circuit 1111. Useful embodiments include a dualprocessor 1113 and a dual communications circuit 1115 and dual on-diememory 1117 such as SRAM. In an embodiment, the dual integrated circuit1111 includes embedded on-die memory 1117 such as eDRAM.

In an embodiment, the electronic system 1100 also includes an externalmemory 1140 that in turn may include one or more memory elementssuitable to the particular application, such as a main memory 1142 inthe form of RAM, one or more hard drives 1144, and/or one or more drivesthat handle removable media 1146, such as diskettes, compact disks(CDs), digital variable disks (DVDs), flash memory drives, and otherremovable media known in the art. The external memory 1140 may also beembedded memory 1148 such as a first die in a die stack, according to anembodiment.

In an embodiment, the electronic system 1100 also includes a displaydevice 1150, and an audio output 1160. In an embodiment, the electronicsystem 1100 includes an input device such as a controller 1170 that maybe a keyboard, mouse, trackball, game controller, microphone,voice-recognition device, or any other input device that inputsinformation into the electronic system 1100. In an embodiment, an inputdevice 1170 is a camera. In an embodiment, an input device 1170 is adigital sound recorder. In an embodiment, an input device 1170 is acamera and a digital sound recorder.

As shown herein, the integrated circuit 1110 can be implemented in anumber of different embodiments including a semiconductor package havinga shielding layer containing metal particles, e.g., conductive particlesor magnetic particles, in a resin matrix to attenuate electromagneticinterference, according to any of the several disclosed embodiments andtheir equivalents, an electronic system, a computer system, one or moremethods of fabricating an integrated circuit, and one or more methods offabricating an electronic assembly that includes a semiconductor packagehaving a shielding layer containing metal particles, e.g., conductiveparticles or magnetic particles, in a resin matrix to attenuateelectromagnetic interference, according to any of the several disclosedembodiments as set forth herein in the various embodiments and theirart-recognized equivalents. The elements, materials, geometries,dimensions, and sequence of operations can all be varied to suitparticular I/O coupling requirements including array contact count,array contact configuration for a microelectronic die embedded in aprocessor mounting substrate according to any of the several disclosedsemiconductor packages having a shielding layer containing metalparticles, e.g., conductive particles or magnetic particles, in a resinmatrix to attenuate electromagnetic interference embodiments and theirequivalents. A foundation substrate may be included, as represented bythe dashed line of FIG. 11. Passive devices may also be included, as isalso depicted in FIG. 11.

Embodiments of semiconductor packages having a shielding layer toattenuate EMI, and methods of forming such semiconductor packages, aredescribed. In an embodiment, a semiconductor package includes a packagesubstrate, a semiconductor die mounted on the package substrate, apolymer layer over the semiconductor die, and a shielding layer over thepolymer layer. The shielding layer includes several metal particles in aresin matrix to attenuate electromagnetic interference (EMI).

In one embodiment, the several metal particles include severalconductive particles electrically connected to each other in the resinmatrix.

In one embodiment, the conductive particles attenuate EMI having afrequency greater than 1 GHz.

In one embodiment, the semiconductor package further includes agrounding pad on the package substrate, and a via extending through theshielding layer and the polymer layer to the grounding pad toelectrically connect the shielding layer to the grounding pad.

In one embodiment, the several metal particles include several magneticparticles.

In one embodiment, the magnetic particles attenuate EMI having afrequency in a range of 500 MHz to 18 GHz.

In one embodiment, the several metal particles include severalconductive particles and several magnetic particles. The shielding layerincludes a first layer having the several conductive particleselectrically connected to each other in the resin matrix, and a secondlayer having the several magnetic particles.

In an embodiment, a semiconductor package assembly includes asemiconductor package and a circuit board. The semiconductor packageincludes a package substrate, a semiconductor die mounted on the packagesubstrate, a polymer layer over the semiconductor die, and a shieldinglayer over the polymer layer. The shielding layer includes several metalparticles in a resin matrix to attenuate electromagnetic interference(EMI). The semiconductor package is mounted on the circuit board.

In one embodiment, the several metal particles include severalconductive particles electrically connected to each other in the resinmatrix.

In one embodiment, the conductive particles attenuate EMI having afrequency greater than 1 GHz.

In one embodiment, the semiconductor package assembly further includes agrounding pad on the package substrate, and a via extending through theshielding layer and the polymer layer to the grounding pad toelectrically connect the shielding layer to the grounding pad.

In one embodiment, the semiconductor package assembly further includes agrounding pad on the circuit board, and a grounding structure extendingfrom the shielding layer to the grounding pad to electrically connectthe shielding layer to the grounding pad.

In one embodiment, the several metal particles include several magneticparticles.

In one embodiment, the magnetic particles attenuate EMI having afrequency in a range of 500 MHz to 18 GHz.

In one embodiment, the shielding layer includes a first layer havingseveral conductive particles electrically connected to each other in theresin matrix, and a second layer having several magnetic particles.

In an embodiment, a method of fabricating a semiconductor package havinga shielding layer includes applying a mold release film to a recessedsurface of a molding chase. The mold release film includes a shieldinglayer having several metal particles in a resin matrix. The methodincludes placing the molding chase over a package substrate to create acompartment between the shielding layer and the package substrate. Asemiconductor die is mounted on the package substrate within thecompartment. The method includes transferring a polymer into thecompartment. The transferred polymer forms a polymer layer over thesemiconductor die between the shielding layer and the package substrate.The method includes transferring the shielding layer from the recessedsurface to the polymer layer.

In one embodiment, the mold release film includes a base film betweenthe recessed surface and the shielding layer. The base film includes aglass transition temperature in a range of 80 to 125 degrees Celsius.

In one embodiment, transferring the shielding layer includes curing thetransferred polymer.

In one embodiment, the method further includes forming a via through theshielding layer and the polymer layer to a grounding pad on the packagesubstrate to electrically connect the shielding layer to the groundingpad.

In one embodiment, the method further includes mounting the packagesubstrate on a circuit board having a grounding pad. The method includesattaching a grounding structure to the shielding layer and the groundingpad to electrically connect the shielding layer to the grounding pad.

What is claimed is:
 1. A semiconductor package, comprising: a packagesubstrate; a semiconductor die mounted on the package substrate; apolymer layer over the semiconductor die; a shielding layer over thepolymer layer, wherein the shielding layer includes a plurality of metalparticles in a resin matrix to attenuate electromagnetic interference;and a grounding structure extending from the shielding layer to agrounding pad to electrically connect the shielding layer to thegrounding pad, wherein the grounding structure is a via extendingthrough the polymer layer to the grounding pad on the package substrate,wherein the via extends through the shielding layer.
 2. Thesemiconductor package of claim 1, wherein the plurality of metalparticles include a plurality of conductive particles electricallyconnected to each other in the resin matrix.
 3. The semiconductorpackage of claim 2, wherein the plurality of metal particles include aplurality of magnetic particles.
 4. The semiconductor package of claim3, wherein the shielding layer includes a first layer having theplurality of conductive particles, and a second layer having theplurality of magnetic particles.
 5. The semiconductor package of claim1, wherein the grounding pad is laterally beside the semiconductor diebetween the polymer layer and the package substrate.
 6. A semiconductorpackage assembly, comprising: a circuit board; a semiconductor packagemounted on the circuit board, the semiconductor package including apackage substrate, a semiconductor die mounted on the package substrate,a polymer layer over the semiconductor die, and a shielding layer overthe polymer layer, wherein the shielding layer includes a plurality ofmetal particles in a resin matrix to attenuate electromagneticinterference; and a grounding structure extending from the shieldinglayer to a grounding pad to electrically connect the shielding layer tothe grounding pad, wherein the grounding pad is on the packagesubstrate, and wherein the grounding structure includes a via extendingthrough the polymer layer to the grounding pad wherein the via extendsthrough the shielding layer.
 7. The semiconductor package assembly ofclaim 6, wherein the plurality of metal particles include a plurality ofconductive particles electrically connected to each other in the resinmatrix.
 8. The semiconductor package assembly of claim 7, wherein theplurality of metal particles include a plurality of magnetic particles.9. The semiconductor package assembly of claim 8, wherein the shieldinglayer includes a first layer having the plurality of conductiveparticles, and a second layer having the plurality of magneticparticles.
 10. The semiconductor package assembly of claim 6, whereinthe grounding pad is on the circuit board, wherein the semiconductorpackage includes a peripheral side, and wherein the grounding structureextends along the peripheral side from a first contact point on theshielding layer to a second contact point on the grounding pad.
 11. Thesemiconductor package assembly of claim 10, wherein the groundingstructure includes one or more of a metallized can, a metallized cloth,an electrical lead, or a film attached to the shielding layer at thefirst contact point and attached to the grounding pad at the secondcontact point.
 12. A method, comprising: mounting a semiconductor die ona package substrate; forming a polymer layer over the semiconductor die;forming a shielding layer over the polymer layer, wherein the shieldinglayer includes a plurality of metal particles in a resin matrix toattenuate electromagnetic interference; and forming a groundingstructure, wherein the grounding structure extends from the shieldinglayer to a grounding pad to electrically connect the shielding layer tothe grounding pad, wherein the grounding pad is on the packagesubstrate, and wherein forming the grounding structure includes forminga via through the polymer layer to the grounding pad to electricallyconnect the shielding layer to the grounding pad, wherein forming thegrounding structure includes forming the via through the shieldinglayer.
 13. The method of claim 12, wherein the grounding pad is on acircuit board, and wherein forming the grounding structure includesmounting the package substrate on the circuit board, attaching thegrounding structure to a first contact point on the shielding layer, andattaching the grounding structure to a second contact point on thegrounding pad.
 14. The method of claim 13, wherein the groundingstructure includes one or more of a metallized can, a metallized cloth,an electrical lead, or a conductive film attached to the shielding layerat the first contact point and attached to the grounding pad at thesecond contact point.